Sleep Calculator
Find the ideal bedtime based on sleep cycles so you wake up feeling refreshed.
2026 Tax YearData stays on your deviceUpdated Apr 1, 2026
Includes ~15 min to fall asleep
Bedtimes are calculated based on 90-minute sleep cycles counted backwards from your wake-up time.
Best Bedtime (6 cycles)
9:45 PM
9 hours of sleep — optimal
Good (5 cycles)
11:15 PM
7.5 hours of sleep
Minimum (4 cycles)
12:45 AM
6 hours of sleep
Recommended Sleep by Age
Teens (14-17)8-10 hrs
Adults (18-64)7-9 hrs
Seniors (65+)7-8 hrs
Frequently Asked Questions
Why are sleep cycles 90 minutes?
A complete sleep cycle includes light sleep, deep sleep, and REM stages, typically lasting about 90 minutes. Waking at the end of a cycle (rather than in the middle) helps you feel more alert and rested.
How many sleep cycles do I need?
Most adults need 5-6 cycles (7.5-9 hours) per night. Some people function well on 4 cycles (6 hours), but this is uncommon. Consistently sleeping fewer than 5 cycles can lead to sleep debt.
Does it matter what time I go to sleep?
Yes. Earlier sleep (before midnight) tends to include more deep sleep, which is critical for physical restoration. Consistency in your sleep schedule is more important than the exact time.
Official Data Sources
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Built and reviewed by Konstantin Iakovlev · Data from CRA, CMHC, Bank of Canada · MethodologyDisclaimer: This calculator provides estimates based on publicly available data from CRA and other government sources. It does not constitute financial advice. Consult a qualified advisor for decisions about your specific situation.
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